[SEL] Not Quite OT: Gray Motor (And Hammond Organ) Trivia

[Dave Croft]

----- Original Message ----- 
From: "John Culp" <johnculp at chartertn.net>
To: "The SEL email discussion list" <sel at lists.stationary-engine.com>
Sent: Wednesday, January 19, 2005 2:15 PM
Subject: [SEL] Not Quite OT: Gray Motor (And Hammond Organ) Trivia


> I love mechanical devices, electronics (mainly of the vacuum tube sort) 
> and music. I've gotten interested in old Hammond organs, which combine 
> all 3. I'm reading a book on them right now, and learned that Laurens 
> Hammond, the thoroughly nonmusical, tone-deaf, mechanically brilliant 
> engineer who invented the organ, served as the Chief Engineer of the 
> Gray Motor Company from 1918-1920. He didn't really like that job and 
> was able to leave it when he invented a silent spring-driven clock 
> movement. He was the inventor of the synchronous AC motor clock, which 
> was responsible for the standardization and close regulation of power 
> line frequency across the US. (He gave electric clocks to the 
> executives of the power companies. That did the trick.) An early 
> invention, when he was 10 and living in France, was an automatic 
> transmission for cars. He didn't follow his mother's advice to show it 
> to Renault's chief engineer, however. He invented the two-color 3D film 
> viewing goggles, guidance systems for glide bombs, missiles and 
> torpedos, and assorted other stuff. Not to mention the Hammond organ, 
> which every modern electronic keyboard attempts to emulate. The 
> spinning tone wheel and magnetic pickup tone generator of the Hammond 
> was derived from the Telharmonium, a 1909 invention of Thaddeus Cahill 
> that used big toothed gears as the pole pieces of huge alternators that 
> generated musical AC frequencies directly (no amplification) that would 
> be piped over telephone lines to speakers in subscribers' homes. The 
> parts of the instrument had to be shipped in 5 railroad cars!
> Anyway, thought y'all'd like to know his Gray Motor Company collection, 
> especially you marine engine enthusiasts. :-)
> John Culp

Hi John, about 20 years ago I had a part time job repairing electric organs.
I just did this to provide my beer money! The circuits were mainly I/C's on
the PCB's. I still have a folder of circuit diagrams & I think I also have a bag 
of I/C's somewhere.
I only worked on one large Hammond & I was horrified when I took the back 
off to find all the horizontal revolving shafts with the tone wheels instead of circuit boards.
I only survived that job because my day job was an Electro-Mechanical 
*telephone exchange engineer. (*Central Office engineer in American)
Most Hammonds had disappeared even then. 
Dave Croft
Warrington
England
http://community.webshots.com/user/crftdv